hatching frog & toad eggs

A smile is currently lingering while typing these words thinking back to how much fun this was for us as kids. We’re tempted to try this again. All of these photos are from our froggy adventures.

It’s such a timeless family project. It’s fun and inexpensive, while also being educational – teaching patience, responsibility, and noticing the details, as well as gentle care for fragile creatures.

There’s little required to get started, and it’s not nearly as complicated as you might think.

Before you begin

First, check your local laws on collecting and releasing local non-endangered eggs, as it varies from location to location.

Please do not purchase eggs from suppliers or online, as there is a high risk of introducing potentially damaging invasive species to your local ecosystem.

Once hatched, froglets should be returned exactly where you found them. Moving frogs between different ponds increases the risk of spreading disease or invasive non-native plants.

One batch of eggs may contain hundreds of eggs, so please be respectful of their little lives and don’t collect more than you can properly care for.

Housing supplies

This entirely depends on how fancy you want to get. Go super frugal, or select a small set-up to last for other adventures. I had four aquariums growing up, and countless bug jars…our poor mother.

Container: Clear containers are best for observation. Larger containers with modest numbers of tadpoles will be less work, as more diligence is needed to keep the water clean and oxygenated in smaller or overcrowded ones. If you use something from home, make sure nothing toxic was stored in it before. A longer, more rectangular shape is better than tall and narrow.

Container Option 1: plastic or glass container you have repurposed, or something inexpensive like this plastic habitat, medium, only large enough for a few tadpoles

Container Option 2: Great for an all included package, options like this 10-gallon are good especially if you want to make a small investment that can be re-used for other hobbies and pets. I would recommend setting the included filter to the lowest setting possible and adding a sponge like this to the suction part of the filter so the tiny tadpoles don’t get sucked into it!

Pawfly MA-60 Quiet Aquarium Air Pump for 10 Gallon with Accessories Air Stone Check Valve and Tube, 1.8 L/min

Oxygen: Air pump with a small airstone. Tadpoles don’t like agitated water, just a gentle bubbling. TIP: a large filter is unnecessary, unless you’re very careful with the choice as they can suck up the tadpoles and create too much current. Plus they are pricier.

Rocks & plants: Place a couple of large rocks, pond weeds, or java moss or duckweed (available at aquarium stores) in the tank. Eventually you will need to build a slope with rocks, gravel, or pond mud when the tadpoles start developing legs (see “metamorphosis begins” later in this article) so they have somewhere to rest.

Water: The best is to collect extra pond water while collecting eggs. Using pond water will bring home good bacteria to keep your tadpoles happy and you don’t have to worry about chorine. If you need to top it up with tap water, it’s VERY IMPORTANT to let the tap water sit for THREE days before using it to allow the chlorine to evaporate, or use Seachem Prime water conditioner, a few drops removes chlorine, chloramine, detoxifies ammonia, nitrate and nitrite.

Optional for Cleaning: a turkey baster can be used to help remove unwanted food/dirt from the bottom of the tank, but it’s not necessary (see “water” in these instructions). Or if you plan on keeping the aquarium for fish, a gravel cleaner would work too.

A notebook or camera for a Metamorphosis Diary. We do have a separate article about age appropriate cameras for kids if you’re curious (See Photography for Kids)

This is my terrifically geeky detailed cycle drawn around age 10.

setting up

Choose a location indoors or outdoors that is bright and gets some sun to allow algae to develop. The tadpoles will eat algae, and algae also helps to purify the water and increase oxygen levels.

But be careful if the spot gets a lot of sunshine. Monitor the temperature so that it reaches no more than 27°C/80°F. You don’t want crispy fried tadpoles.

Housing outdoors will allow rain water and mosquito larvae for the tadpoles to eat. Just make sure it doesn’t freeze!

A secure lid with air holes will be needed to prevent birds and cats from eating the eggs, and then, as they start becoming frogs, to prevent them from climbing out themselves.

It’s a good idea to keep about 5-10 tadpoles per liter of water. You can keep more, but they may die out faster or become carnivorous (so one cluster of eggs per large container).

Important: NEVER clean the container or anything you put into it with soap, detergent, vinegar or any other cleaning solutions. Only use water! Anything else is toxic to the little ones.

When to collect?

This varies depending on the species, and the climate where you live.

In colder climates here in Canada, starting in late March you can start listening for frog and toad calls. Further North where it’s colder, this delays into April-May. Spring peepers and wood frogs are typically earlier, but larger frogs like bullfrogs may call late, such as June-July.

Your local area may have a nifty list to get you excited about what species are near your home, and even may have some frog calls for you to listen to! Listen carefully and you might be able to discover which frog species you’re collecting.

For example: Frog Watch

Supplies for collecting

  • Rubber boots (or hip waders)
  • Net or scoop
  • Rain gear just in case!
  • One bucket for eggs (at least 1L to allow enough oxygen for the trip home and to keep the water from getting too warm too quickly)
  • One larger bucket to bring home extra pond water (this is important to bring good bacteria into the home set-up)
  • Scissors
  • If it’s a long trip home or if you like a warm car, consider a cooler to keep the eggs from getting too hot (and maybe using buckets with lids for the bumps along the road)
  • Camera to take some snaps of the fun

Where to collect

Early evening is usually the best time to try and listen for frog choruses, though early in the season this can even be mid-day. Look in small streams, creeks, ditches, ponds or depressions in fields or forests. Scan for areas where there is dead grass, weeds, or vegetation like cattails, as the dark masses of eggs are often deposited there. Just listen and look!

how to collect

It’s best to scoop them directly into a container.

Or if using a net, scoop them gently and draw them towards you without lifting the eggs from the water, then put them in the container.

If you need to split up a large batch of eggs just use sharp scissors. The individual eggs are surrounded by hard jelly and attached together into a mass with softer jelly. Gently cut the soft gel part and avoid the eggs themselves. You won’t need to do this it you are taking the whole batch.

Fill an extra bucket with pond water and take it home for the home set-up.

If you are expecting a long trip home or like the heater at full blast, pop them in the cooler and keep away from the heat vents.

keeping it clean

It’s important to keep the water clean and oxygenated.

Bacteria and lack of circulation can quickly use up all the oxygen and the tadpoles will suffocate. This can happen overnight!

If the water goes cloudy, begins to smell foul, or if tadpoles are lingering near the surface, exchange part of the water (up to 30% at a time, once every 6 hours or so) until it’s clear again.

Be sure that the new water is close to the same temperature as the water already in the tank – drastic changes in water temperature can kill your tadpoles.

And remember: Using more pond water is best. Avoid using chlorinated water but if you need to, let it stand for a few days first to allow chlorine to evaporate then mix it with some rain water. Or, you can use a water conditioner like what is used in aquariums, as mentioned in the supplies list.

TIP: See the note about using a turkey baster or gravel cleaner in the supplies list

food

  • Lettuce, romaine or green leaf only. Boil for a few minutes until soft and squishy, cut into smaller pieces, and let them float in the water. Do not use cabbage or iceberg lettuce.
  • Occasionally supplement the lettuce with slices of cucumber, pre-soaked in non-chlorinated water
  • A few pond leaves with algae on them
  • They’ll also eat algae in the tank and any pond critters that hitched a ride every time you added fresh pond water.

Be careful not to overfeed. Feed only what the tadpoles can eat in an hour to avoid fouling the water. Remove any uneaten food within the hour. Too much food can cause death to the tadpoles from over eating.

Tadpoles don’t actively feed for the first 3-5 days, as they will rely on the protein from their eggs yolks when they hatched. When they start swimming around, it’s time to start feeding.

Do not feed the tadpoles when they have sprouted arms. At this time the tadpole will be using its tail as food and it will become an adult frog (see below “metamorphosis begins”).

metamorphosis

After 20-30 days from hatching (at room temperature) you will see tiny hind legs start to appear.

40-60 days from hatching, the tadpoles are full grown and ready to transform. They will stop eating. Transformation becomes much more rapid at this point. Fat little tadpoles with legs will become tiny frogs with shrunken tails in 5-7 days.

Once the tadpoles’ hind legs appear, you need to rework the landscape. As they transform and switch from gills to lungs, they need to be able to emerge from the water and rest. Provide a gently sloping spot where the froglets can crawl out of the water, like with a pile of rocks or driftwood, but avoid all types of treated lumber.

This “land” area should be against an edge of the tank, not in the middle, as some species will only look along the edge for a place to emerge, swimming until they become exhausted and drown. Make sure your tank has a secure lid, as wet froglets and toadlets can climb glass.

There will be some variation in growth rates among a batch of tadpoles, so you’ll need to adjust the amount of food given to allow the slower ones to keep growing. Be careful not to overfeed at this point.

Keep that in mind but don’t panic when it gets cold; in winter the tadpoles will grow more slowly. The ideal temperature is between 20°-25°C / 68°-77°F.

Release

Timely release of tadpoles is critical. When your tadpoles begin to come out of the water to breathe, it’s a signal that they have metamorphosed from vegetarian to carnivore. As soon as they have completely lost their tails it’s time to quickly release them. Enjoy the thrill of seeing them swim away home!

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